Under circumstances where individuals such as workers, sports spectators and the like are present in a warm environment such as when out of doors in bright sunshine those persons can become quite uncomfortable especially in the region of the head. Since a protective hard hat for workers is usually essential for safety it should not be taken off for extended periods in the working environment to provide for cooling of the head and face of the user. There is therefore often a need to compensate for the hot conditions of the environment by providing an air blowing system for liberating heat from about the user's head for the purpose of cooling while allowing the user to continuously wear the hard hat or helmet.
Under circumstances where the user is a worker, working in hot or otherwise inclement conditions, though motorized cooling is desired for the safety hat of the user nevertheless it is necessary to maintain the impact resistant structural integrity of the hard hat in order to maintain the integrity of the head protection that is needed by the worker. For this reason it is highly desirable that the domed shell of the hard hat not be perforated, cut or altered in any manner that could weaken it.
In the past, safety type helmets for workers have been developed which employ an air blowing system particularly for cooling the head of the user and also for cooling the face of the user. One example of air blowing type safety hard hats is indicated by U.S. Pat. No. 4,893,356 of Waters which employs a hard hat 14 having its frontal portion cut away as shown at 16 so that a motorized fan mounted externally of the hard hat can blow air through the opening 16 for cooling the head of the user. Since the cut away portion is for the most part defined in the front wall of the domed protective shell portion of the hard hat, the structural integrity of the hard hat is materially decreased. Consequently the type of air blowing hard hat construction shown in FIG. 1 of the patent to Waters would not likely be acceptable because the hard hat is materially weakened. Other hats, including hard hats that are provided with motor operated blowing systems for the purpose of cooling, are indicated by U.S. Pat. Nos. 3,168,748 of Limberg, 3,881,198 of Waters, 4,141,083 of Waters, 4,680,815 of Hirsch, et al., 4,546,496 of Lewis, 5,085,231 of Johnson. None of the prior art patents both provide air blowing systems for safety type hard hats or helmets which maintain the structural integrity of the domed shell portion of the helmet while at the same time providing for refreshing and cooling flow of air downwardly along the face of the user for the purpose of cooling. Further, none of the prior art references disclose or inherently suggest a motorized fan operated air blowing system for a hard hat or rigid helmet which provides an air ducting system having an inlet and a narrow, elongate discharge slot for directing air downwardly along the front portion of the shell of the helmet but exteriorally of the shell for a curtain of flowing air along the face of the user. Even further, none of the prior art references disclose or suggest an air blowing system having an air inlet through which air is drawn by a motor operated fan and an air discharge outlet wherein the velocity of air being discharged from the outlet is greater than the velocity of air being drawn through the inlet by the fan mechanism by virtue of a venturi effect that is developed by the configuration of the air flow passage.